Inorganic organic coester stabilizers

ABSTRACT

New polyhydric phenol coesters are disclosed of polyhydric phenols, having 2 to 3 phenolic hydroxyl groups and 1 to 3 benzenoid rings, with carbonic acid and an inorganic acid which can be phosphorous acid, phosphoric acid, and boric acid. The new coesters have molecular weights from 700 to about 10,000, preferably from 1200 to 7000, and are highly effective stabilizers for a variety of synthetic resins. 
     Stabilizer compositions comprising a polyhydric phenol coester and a known polymer stabilizer, as well as synthetic resins stabilized with such stabilizer compositions, are also disclosed.

This is a division, of application Ser. No. 772,994, filed Feb. 28, 1977now U.S. Pat. No. 4,146,517.

BACKGROUND OF THE INVENTION

This invention relates to a new class of polyhydric phenol coesters andto synthetic resin stabilizer compositions comprising these coesters aswell as to synthetic resins stabilized with such coesters and withstabilizer compositions comprising these coesters along with knownpolymer stabilizers.

The usefulness of phenols in stabilizer compositions for syntheticresins was recognized early in the development of polymer stabilizationby additives, as disclosed for example by F. Duggan in U.S. Pat. No.2,126,179 to Aug. 9, 1938, W. Leistner in U.S. Pat. No. 2,564,646 ofAug. 14, 1951, and W. Fischer in U.S. Pat. No. 2,625,521 of Jan. 13,1953, in the stabilization of polyvinyl chloride resin compositions.Over the years, phenolic stabilizers have been used in an expandingvariety of synthetic resins and an enormous number of disclosures of newphenolic stabilizers has accumulated. Rather than attempt to list everyone of these disclosures, A. DiBattista in U.S. Pat. No. 3,824,192 ofJuly 16, 1974 and M. Minagawa in U.S. Pat. No. 3,849,370 of Nov. 19,1974 and in U.S. Pat. No. 3,869,423 of Mar. 4, 1975 are cited assummaries of a very large part of the existing art of phenolicstabilizers.

Phenolic stabilizers are also employed in conjunction with otherstabilizers such as esters of thiodipropionic acid or organic phosphitesin the stabilization of polypropylene and other synthetic resins againstdegradation upon heating or ageing under atmospheric conditions.Disclosures by C. Tholstrup, U.S. Pat. Nos. 3,033,814 of May 8, 1962 and3,160,680 of Dec. 8, 1964; L. Rayner, U.S. Pat. No. 3,181,971 of May 4,1965; D. Bown, U.S. Pat. No. 3,242,135 of Mar. 22, 1966; S. Murdock,U.S. Pat. No. 3,245,949 of Apr. 12, 1966; H. Hagemeyer, U.S. Pat. No.3,282,890 of Nov. 1, 1966; J. Casey, U.S. Pat. Nos. 3,496,128 of Feb.17, 1970 and 3,586,657 of June 22, 1971; M. Minagawa, U.S. Pat. No.3,549,572 of Dec. 22, 1970, and 3,629,189 of Dec. 21, 1971, and3,673,152 of June 27, 1972, 3,849,370 of Nov. 19, 1974 and 3,869,423 ofMar. 4, 1975; W. Drake U.S. Pat. No. 3,624,026 of Nov. 30, 1971; A.DiBattista, U.S. Pat. No. 3,824,192 of July 16, 1974; B. Cook, U.S. Pat.No. 3,850,877 and H. Mueller U.S. Pat. No. 3,850,918 of Nov. 26, 1974;M. Dexter U.S. Pat. No. 3,856,748 of Dec. 24, 1974, and 3,888,824 ofJune 10, 1975, and 3,903,160 of Sept. 2, 1975; P. Klemchuk of U.S. Pat.No. 3,860,558 of Jan. 14, 1975; M. Rasberger U.S. Pat. Nos. 3,867,340 ofFeb. 18, 1975 and 3,901,931 of Aug. 26, 1975; H. Brunetti U.S. Pat. Nos.3,867,337 of Feb. 18, 1975 and 3,873,498 of Mar. 25, 1975; S.Rosenberger U.S. Pat. Nos. 3,884,874 of May 20, 1975 and 3,887,518 ofJune 3, 1975; C. Ramey U.S. Pat. No. 3,907,803 of Sept. 23, 1975 arerepresentative of a very large number of stabilizer combinationsincluding dilauryl and distearyl thiodipropionate or other dialkylthiodipropionates along with polyhydric phenols and sometimes organicphosphites, metallic stearates, ultraviolet absorbers, nickel compounds,and heavy metal deactivators for use in polypropylene and otherpolyolefins.

Disclosures by R. Werkheiser, U.S. Pat. No. 2,726,226 of Dec. 6, 1975;I. Salyer et al, U.S. Pat. No. 2,985,617 of May 23, 1961; L. Friedman,U.S. Pat. No. 3,039,993 of June 19, 1962; W. Nudenberg, U.S. Pat. No.3,080,338 of Mar. 5, 1963; C. Fuchsman, U.S. Pat. No. 3,082,187 of Mar.19, 1963; H. Orloff et al, U.S. Pat. No. 3,115,465 of Dec. 24, 1963; A.Nicholson, U.S. Pat. No. 3,167,526 of Jan. 26, 1965; A. Hecker et al,U.S. Pat. Nos. 3,149,093 of Sept. 15, 1964, 3,244,650 of Apr. 5, 1966and 3,225,136 and 3,255,151 of June 7, 1966; C. Bawn, U.S. Pat. No.3,352,820 of Nov. 14, 1967; D. Miller, U.S. Pat. No. 3,535,277 of Oct.20, 1970; J. Casey, U.S. Pat. No. 3,586,657 of June 22, 1971; C.Abramoff U.S. Pat. No. 3,856,728 of Dec. 24, 1974; M. Minagawa, U.S.Pat. Nos. 3,869,423 of Mar. 4, 1975 and 3,907,517 of Sept. 23, 1975; andBritish Pat. Nos. 846,684, 851,670, and 866,883 are representative ofstabilizer combinations including organic phosphites, polyhydricphenols, and other active ingredients.

As summarized in a publication by D. Plank and J. Floyd (title"Polycarbonates: A New Concept in Stabilization for Polypropylene,"meeting preprints, Society of Plastics Engineers, Houston, Texas, April1975; pages 33-37), there have long been several problems with usingphenols as stabilizers despite their widespread use. Many phenolstabilizers are volatilized out of the polymer at high use temperatures.Some phenol stabilizers are extractable under certain use conditions.The oxidative products of most phenols are highly colored, thusimparting a yellow color to the polymer. Many phenols are reactivetowards acidic or basic residues in the polymer. Following aredisclosures of suggested ways to overcome these problems.

L. Friedman has disclosed in U.S. Pat. No. 3,053,878 of Sept. 11, 1962 aclass of linear phosphite polymers having the formula ##STR1## In whichQ is the alkylene or arylene portion of a dihydric alcohol or dihydricphenol. R. Morris et al. in U.S. Pat. No. 3,112,286 of Nov. 26, 1963disclosed phosphites having the formula ##STR2## in which R represents abulky hydrocarbon group such as t-butyl, t-amyl, t-hexyl, cyclohexyl,t-pentyl, t-octyl, phenyl, and the like: R₁ represents hydrogen and R;R₃ represents an alkyl group from 6 to 20 carbon atoms which ispreferably in the meta or para position; x represents a number of from 1to 3 inclusive; y represents a number of from 0 to 2 inclusive and thesum of the numerical value of x+y is always exactly 3.

D. Bown, U.S. Pat. No. 3,297,631 of Jan. 10, 1967 disclosed condensationproducts of phosphorus compounds with bisphenols and trisphenols whichmay be represented by the structures: ##STR3## Where:

X is selected from the following: >P--OR'; >P--R'; ##STR4##

and Y is selected from the following: --P(OR')₂ ; ##STR5## R ishydrogen, alkyl of 1 to 16 carbon atoms or aryl or a combination ofthese; R' is alkyl of 1 to 16 carbon atoms or aryl, and R" is alkylideneof 1 to 16 carbon atoms or an aryl-substituted alkylidene.

C. Baranauckas, U.S. Pat. No. 3,305,608 of Feb. 21, 1967, disclosedphenolic phosphites useful as polymer stabilizers prepared by reacting atriorganophosphite, a polyol, and an aromatic material having two to sixphenolic hydroxyl groups at 60°-180° C. in specific proportions.

G. Brindell, U.S. Pat. No. 3,412,064 of Nov. 19, 1968 disclosed phenolicphosphites represented by the general formula: ##STR6## where x is from1 to 3, y and z each from 0 to 2, x+y+z=3, R is hydrogen or alkyl and Yis hydroxyl or a group of the formula ##STR7##

M. Larrison, U.S. Pat. No. 3,419,524 of Dec. 31, 1968, disclosedphosphites useful as polymer stabilizers having the formula: ##STR8##where R₁, R₂, R₄, R₆, and R₇ are aryl or haloaryl, and R₃ and R₅ are apolyalkylidene glycol or an alkylidene bisphenol or a hydrogenatedalkylidene bisphenol or a ring halogenated alkylidene bisphenol fromwhich the two terminal hydrogens have been removed.

O. Kauder et al, U.S. Pat. Nos. 3,476,699 of Nov. 4, 1969 and 3,655,832of Apr. 11, 1972 disclosed organic phosphites containing a free phenolichydroxyl group and defined by the formula: ##STR9## wherein Z isselected from the group consisting of hydrogen and aliphatic,cycloaliphatic, aromatic, heterocyclic and (Ar)_(p) -Y-Ar groups, takenin sufficient number to satisfy the valences of the two phosphite oxygenatoms; Y is a polyvalent linking group selected from the groupconsisting of oxygen; aliphatic, cycloaliphatic and aromatic hydrocarbongroups attached to each Ar group through a carbon atom not a member ofan aromatic ring; oxyaliphatic; thioaliphatic, oxycycloaliphatic,thiocycloaliphatic; heterocyclic; oxyheterocyclic, thioheterocyclic,carbonyl, sulfinyl; and sulfonyl groups; Ar is a phenolic nucleus whichcan be phenyl or a polycarbocyclic group having condensed or separatephenyl rings; each Ar group is either connected through an oxygen atomto a phosphite group or contains a free phenolic hydroxyl group, orboth; and p is a number, one or greater, and preferably from one tofour, which defines the number of Ar groups linked to Y.

L. Friedman, U.S. Pat. No. 3,516,963 of June 23, 1970, disclosedphosphites having the formula ##STR10## where R is alkyl, alkenyl, aryl,aralkyl, haloaryl, haloalkyl or ##STR11## and n is an integer of atleast 1. n can be 2, 3, 4, 5, 6, 7, 8, 10, 50, 100 or even more.

D. Bown et al. in U.S. Pat. Nos. 3,510,507 of May 5, 1970 and 3,691,132of Sept. 12, 1972 disclosed polyolefins stabilized with polyphosphites,polyphosphates, polyphosphonites, polyphosphonates, polyborates,polycarbonates, and polysilanes which are condensation products of a4,4'-bisphenol with a condensing or linking agent which may be of theester type, such as the esters of triaryl or mixed aryl-alkyl compounds,or the acid halide type. Bown's condensation product stabilizers havemolecular weights between 600 and 8000 or higher and are described bythe structural formula, ##STR12## where X is selected from the groupconsisting of ##STR13## --C--C, and C--A--C-- where

A is a C₁ to C₁₆ alkylene or an arylene; R', R", R'", and R"" areselected from the group consisting of hydrogen, C₁ to C₁₈ alkyls, and anaryl group; Y is selected from the group of ##STR14## where R ishydrogen, a C₁ to C₁₈ alkyl, or aryl; ##STR15## where m is 0 to 10,preferably 4 to 8, ##STR16## where A' is (CH₂)_(n) --S--(CH₂)_(n) or--(CH₂)_(n) --S--(CH₂)_(m) --S--(CH₂)_(n) where n is 0 to 10, preferably2 and m is 0 to 10, preferably 5; ##STR17## where R is an alkyl,preferably methyl, and Z is ##STR18## where R', R", R'", R"", and Xcorrespond respectively to the R', R", R'", R"", and X previouslyselected when n has a value from 1 to 15, or Z may be derived from thecompound used to introduce Y into the product when n has a value from 2to 15, for example --R or --OR where R is hydrogen, an alkyl, or aryl.When Y in the formula of Brown's stabilizer is ##STR19## the stabilizeris a type of hydroxyaryl phosphite. Similarly, when Y in the formula is##STR20## the stabilizer is a hydroxyaryl carbonate.

Bown's condensation products are described as especially effective inhigh molecular weight solid polyolefins when used together with adialkyl sulfide costabilizer such as dilauryl thiodipropionate,distearyl thiodipropionate, ditridecyl thiodipropionate, dicetylsulfide, bis(tetradecylmercapto) paraxylylene, and10,24-dithiotetracontane.

J. Floyd et al in German published application 2505071 of Aug. 14, 1975abstracted in Chemical Abstracts 1976, Volume 84, abstract no. 5945f,disclosed low molecular weight polycarbonate esters of bisphenols suchas 2,2-bis(3-t-butyl-4-hydroxyphenylpropane) and 4,4'-butylidenebis(6-t-butyl-3-methylphenol) prepared in such a way as to contain fewor no free phenolic hydroxyl groups as being highly effective heat andlight stabilizers for polyolefins and giving a synergistic effect withdistearyl thiodipropionate, tris (nonylphenyl) phosphite, and distearylpentaerythritoldiphosphite.

D. Plank and J. Floyd in the 1975 publication already cited havedisclosed two general synthetic procedures for preparing stabilizerpolycarbonates. They may be obtained by direct phosgenation of abisphenol either in methylene chloride with pyridine as a catalyst ordirectly in pyridine. Using this procedure, a typical product obtainedhas the following formula. ##STR21##

The authors did not state the nature of R or a value of n but didindicate that the molecular weight can be controlled easily by adding amodifier to the reaction mixture. The nature of the modifier is notmentioned. The authors disclosed a range of molecular weights from 680to 1952, with the highest molecular weight products providing thelongest 150° C. oven life in polypropylene also containing a thioester,distearyl thiodipropionate. The authors stated that when used alone, twoproducts within their class of polycarbonates are not effectivestabilizers, but they formed a very effective stabilizing system incombination with a thioester.

In other disclosures of polyhydric phenol carbonate ester additives tosynthetic resin compositions, H. Peters in German Pat. No. 1,146,251 ofMar. 28, 1963 improved mechanical properties of polyolefins by adding0.5 to 50% 2,2bis(4-hydroxyphenylpropane) carbonic acid polyester. T.Saito in U.S. Pat. No. 3,364,281 of Jan. 16, 1968 disclosed polyolefinfibers of improved dyeability containing 1 to 20% of polymeric additivewhich can be a high molecular weight polyhydric phenol carbonate. Solvayet Cie. in British Pat. No. 1,135,976 of Dec. 11, 1968 has disclosed theuse of a high molecular weight bis(hydroxyphenyl) propane-phosgenecondensation product as an adjunct to the polymerization initiator forthe polymerization of ethylene. I. Ouchi in Japanese Pat. No. 69-21,676of Sept. 16, 1969 improved the smoothness of polyethylene terephthalatefilm by incorporating a small percentage of polycarbonate. Z. Opritz inUSSR Pat. No. 314,827 of Sept. 21, 1971 disclosed improved heatresistance of polyamides prepared from amino acids or lactams byaddition of up to 10% of a polycarbonate having a formula (OC₆ H₄ RC₆ H₄O₂ C)_(x) where R is CH₂, CMe₂, or C(C_(n) H_(2n+1))₂. Y. Umezawa inJapanese Kokai 72-34,744 of Nov. 22, 1972 disclosed styreneacrylonitrilecopolymer compositions having improved moldability and mechanicalproperties with 5 to 40% polycarbonate resin. None of these disclosuresrelates to a coester of a polyhydric phenol with carbonic acid and adicarboxylic acid or to a carbonate ester of molecular weight less than10,000.

Carbonate esters and carbonate-dicarboxylic acid coesters of polyhydricphenols are known in the form of high molecular weight materials thatare useful as films, fibers, molded or extruded parts and surfacecoatings for use in structural, decorative and electrical applications.The extensive literature has been reviewed by L. Bottenbruch in"Encyclopedia of Polymer Science and Technology" (N. Bikales, ed.)Volume 10, pages 714-725 (J. Wiley--Interscience Publishers, New York1969). High molecular weight coesters including aliphatic dicarboxylicacids in the polymer chain with polyhydric phenol carbonates have beendisclosed by E. Goldberg, in U.S. Pat. Nos. 3,020,331 and 3,030,335 ofApr. 17, 1962, 3,161,615 of Dec. 15, 1964, 3,169,121 of Feb. 9, 1965,and 3,207,814 of Sept. 21, 1965. N. Reinking in U.S. Pat. No. 3,166,606of Jan. 19, 1965 and H. Schnell in U.S. Pat. No. 3,533,167 of Jan. 5,1971.

SUMMARY OF THE INVENTION

In accordance with this invention, new polyhydric phenol coesters ofpolyhydric phenols having 2 to 3 phenolic hydroxyl groups and 1 to 3benzenoid rings with carbonic acid and an inorganic acid selected fromthe group consisting of phosphorous acid, phosphoric acid, and boricacid are prepared. The coesters have molecular weights ranging from 700to about 10,000, preferably from 1200 to about 7000 for highesteffectiveness as ingredients of stabilizer compositions for syntheticresins. The molar proportions of the inorganic acid to the carbonic acidin the coester range from 19:1 to 1:19, preferably from 4:1 to 1:4. Thecoesters of the invention can contain a single polyhydric phenol or aplurality of polyhydric phenols as well as a single inorganic acid or aplurality of inorganic acids.

Synthetic resin stabilizer compositions comprising the coesters of thisinvention contain at least one known polymer stabilizer along with oneor more coesters according to this invention. The proportions of coesterto known polymer stabilizer in such stabilizer compositions can rangefrom 1 to 1 to about 1 to 30 by weight.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Essential to the achievement of the unexpected effectiveness in resinstabilizer compositions of the coesters of this invention are thecombined inorganic-organic structure and controlled molecular weight ofthe polyhydric phenol inorganic acid and carbonic acid coesters. Thereresults from these essential features a minimal volatility andleachability so that the stabilizing effectiveness manifested by thecoesters is maintained over long periods of time where resincompositions stabilized with the coesters are exposed to the action ofair, water, and chemical solutions at an elevated temperature.

The polyhydric phenol inorganic acid-carbonate coesters of thisinvention are derived from carbonic acid, introduced into the moleculeby a carbonylating agent such as an ester or acid chloride of carbonicacid; at least one inorganic acid introduced into the molecule by way ofan ester or acid chloride of the inorganic acid; and a polyhydric phenolhaving two to three hydroxyl groups and one to three benzenoid ringswhich can be substituted with up to three alkyl, cycloalkyl, or aralkylgroups having 1 to 10 carbon atoms. For reasons that are not wellunderstood the greatest stabilizing effectiveness is associated withinorganic acid-carbonic acid coesters of polyhydric phenols having anodd number of benzenoid rings in the polyhydric phenol.

The polyhydric phenol carbonate-inorganic acid coesters of thisinvention are crystalline powders or grindable glassy solids.

A preferred class of polyhydric phenol carbonate-inorganic acid coestersof this invention is derived from ortho-substituted 1,3- and1,4-dihydric phenols having one benzenoid ring such as2,5-di-t-butyl-hydroquinone, 2,3,6-trimethylhydroquinone,2-methylresorcinol, and 2,6-di-t-butylresorcinol.

Also useful polyhydric phenol carbonate-inorganic acid coesters arecoesters of ortho-substituted bisphenols having two ortho-substitutedphenolic groups linked directly or through a two valent hydrocarbongroup such as 2,2'-methylene bis(4-methyl-6-t-butyl-phenol),2,2'-methylene bis(4-ethyl-6-t-butyl-phenol), 2,2'-methylenebis(4-methyl-6-(1-methylcyclohexyl)phenol), 2,2'-n-butylidenebis(4,6-dimethylphenol),bis-1,1-(2'-hydroxy-3'5'-di-methylphenyl)-3,5,5-trimethylhexane,2,2'-cyclohexylidene bis(4-ethyl-6-t-butylphenol),4,4'-bis(2,6-di-t-butylphenol), 4,4'-methylenebis(2,6-di-t-butylphenol), 4,4'-isopropylidene bis(2-phenylethylphenol),4,4'-n-butylidene bis(3-methyl-6-t-butylphenol), 4,4'-cyclohexylidenebis(2-t-butylphenol), 4,4'-cyclohexylidene bis(2-cyclohexylphenol), and4,4'-benzylidene bis(2-t-butyl-5-methylphenol).

Another preferred class of polyhydric phenol carbonate-inorganic acidcoesters provided in accordance with this invention is the class ofcarbonate coesters of ortho-substituted bisphenols havingtwo-ortho-substituted phenolic groups linked through oxygen or sulfur,such as 4,4'-oxobis(3-methyl-6-isopropylphenol),4,4'-thiobis(2-methyl-6-t-butyl phenol),4,4'-thiobis(3-methyl-6-t-butylphenol),4,4'-sulfobis(3-methyl-6-t-butylphenol),bis(2-methyl-4-hydroxy-5-t-butylbenzyl) sulfide,bis(3,5-di-t-butyl-4-hydroxy benzyl)sulfide, 2,2'-thiobis(4-hydroxybenzyl) sulfide, 2,2'-thiobis(4-t-butyl-6-methylphenol),2,2'-thiobis(4-methyl-6-t-butyl-phenol), and2,2'-thiobis(4,6-di-t-butylphenol).

A particularly preferred class of polyhydric phenol carbonate-inorganicacid coesters is the class of carbonate coesters of ortho-substitutedtrisphenols having three ortho-substituted phenolic groups, such as1,1,3-tris(2'methyl-4'-hydroxy-5'-t-butylphenyl)butane,1,3,5-tris(3',5'-di-t-butyl-4'-hydroxybenzyl)-2,4,6-trimethylbenzene,2,2-bis(3'-t-butyl-4'-hydroxyphenyl)-4-(3",5"-di-t-butyl-4"-hydroxyphenyl)butane,and2,2-bis(2'-methyl-5-t-butyl-4'-hydroxyphenyl)-4-(3",5"-di-t-butyl-4"-hydroxyphenyl)butane.

The polyhydric phenol inorganic acid carbonate coesters of thisinvention can be prepared by the reaction of a carbonylating agent suchas phosgene, a chloroformate ester, a dialkyl carbonate of a diarylcarbonate with an inorganic acid compound and a substituted dihydric ortrihydric phenol in one or several reaction stages. Acid acceptors suchas ammonia, pyridine, organic amines, and inorganic alkalines can beused with phosgene and chloroformate esters, and acidic or alkalinetransesterification catalysts can facilitate the reaction of alkyl andaryl carbonate esters. The molecular weight of the coesters is regulatedby the proportions of inorganic acid compound and carbonylating agent todihydric or trihydric phenol. The more closely the proportions of thecombined inorganic acid and carbonylating agent to dihydric or trihydricphenol approach one to one compound equivalent of each reactant thehigher the molecular weight of the resulting product.

Conversely, either reactant can be used in large excess to prepareproducts having nearly the lowest molecular weight possible, that is acoester having a single carbonate ester group, a single inorganic acidester group, and the minimum number of polyhydric phenol groups to linkthese together. Thus the product of the reaction between two moles of adihydric phenol and one mole of carbonylating agent is a relatively lowmolecular weight mixture of carbonate esters in which thebis(hydroxyaryl carbonate) of the dihydric phenol predominates, and theproduct of the reaction between two moles of a carbonate estercarbonylating agent (e.g. diphenyl carbonate) and one mole of dihydricphenol is a relatively low molecular weight mixture of carbonate estersin which the dihydric phenol bis(phenyl carbonate) ester predominates.

Each of these products can then be used to prepare a coester of thisinvention by reaction with an appropriate inorganic acid compound. Thusthe above bis(hydroxyaryl) carbonate ester of the polyhydric phenol canbe caused to condense with the acid chloride or phenyl ester of aninorganic acid, with elimination of hydrogen chloride or phenol as sideproduct respectively, to give a carbonate-inorganic acid coester with amolecular weight depending on the relative proportions of reactants.Similarly, a polyhydric phenol phenyl carbonate ester can betransesterified with a hydroxyaryl ester of an inorganic acid todisplace phenol and give a carbonate-inorganic acid coester of thepolyhydric phenol present in each of the starting materials, which meansthat the coester can be made up of different polyhydric phenols if eachof the starting materials contains a different polyhydric phenol. Bothtechniques just described are essentially two stage reaction techniquesthat yield coesters of a relatively ordered structure in whichpolyhydric phenol groups are alternatively linked through carbonateester groups and through inorganic acid ester groups. Coesters preparedat elevated temperature, such as by the phenol ester transesterificationtechnique, have the ordered alternating structure modified to a minorextract as a result of ester-ester interchange randomization. Thereactions can be illustrated by equations in which for convenience thesymbols HO--Ar--OH and HO--Ar'--OH are used for the polyhydric phenolsthat can be used according to this invention, and (PhO)₃ Z and ZCl₃represent any of the phenyl esters and acid chlorides of inorganic acidsthat can be used.

A. Condensation of hydroxyaryl carbonate with inorganic acid compound:

    2HO--Ar--OH+PhO--CO--OPh→HO--Ar--OCO--OAr--OH+2PhOH

    3HO--Ar--OCO--OAr--OH+ZCl.sub.3 →(HOArOCO--OArO).sub.3 Z

B. Condensation of phenyl carbonate of polyhydric phenol with aninorganic acid ester of a different polyhydric phenol:

    HO--Ar--OH+2 PhO--CO--OPh→PhO--CO--OAr--O--CO--OPh+2PhOH

    PhO--CO--OAr--O--CO--OPh+2(HO--Ar'--O)Z→(HOAr'O).sub.2 ZOAr'OCO--OArOZ(OAr'OH).sub.2

Coesters of this invention can also be prepared in a single reactionstep leading to a random arrangement of carbonic acid ester andinorganic acid ester groups in the structure of the coester. Thus thepolyhydric phenol (or mixture of more than one polyhydric phenols) canbe heated with a mixture of diphenyl carbonate and inorganic acid phenylester with removal of the side-product phenol. Alternatively, thepolyhydric phenol (or mixture of polyhydric phenols) can be reacted,suitably dissolved in an inert solvent such as toluene, methylenechloride or trichloroethylene, with a mixture of inorganic acidtrichloride and carbonyl chloride (COCl₂) or a polyhydric phenolchlorocarbonate ester Ar(OCOCl)₂₋₃ with elimination of by-producthydrogen chloride by reaction with an acid acceptor which can be anorganic amine dissolved in the reaction solution, a suspension of aninorganic alkali, or an aqueous solution of an inorganic alkali. Boththe phenyl ester reaction and the acid chloride reaction can befacilitated by the use of catalysts. The phenyl ester reaction issuitably catalyzed by substances of sufficient alkalinity to convertphenol at least in part to the phenoxide ion, such as alkali andalkaline earth metals and their oxides, hydroxides, sulfides, cyanides,phenolates, hydrides, alcoholates, and carboxylates as well as aliphaticand cycloaliphatic amines, preferably tertiary amines to avoid thepossible complication of amide formation. Suitable catalysts for theacid chloride reaction include tertiary amines, tertiary phosphines, andthe hydrogen halide and alkyl halide addition salts thereof. Catalystconcentrations usefully range from 0.01% to about 5% by weight ofreaction mixture. Preferred catalysts for the acid chloride reactionhave the ability to partition between water and an immisciblehydrocarbon phase with a partition coefficient between 0.01 and 100.

Both the phenyl ester reaction method of preparing the coester of thisinvention and the acid chloride method can be carried out over aconvenient range of reaction temperatures. The phenyl ester reaction isconveniently carried out at elevated temperatures of the order of 80° to210° C. with removal of the side product phenol by distillation,suitably under diminished pressure. It is frequently helpful to beginthe reaction by an atmospheric pressure cook, suitably with nitrogen orother inert gas protection over the reaction mass to preserve its lightcolor, and apply vacuum gradually after a quantity of side product hasaccumulated for removal.

The acid chloride reaction is conveniently carried out at ambienttemperatures or as cold as -15° C. Elevated temperatures in the 40° to90° C. range can also be used.

In coesters prepared with an excess of equivalents of the dihydric ortrihydric phenol reactant over the equivalents of carbonylating agentand inorganic acid compound combined, the coester is predominantlyterminated by hydroxyaryl groups, while in coesters prepared with anexcess of the combined equivalents of inorganic acid compound andcarbonylating agent over the phenol, ester termination predominates. Thehydroxyaryl terminated coesters having an average molecular weightranging from 700 to about 10000 and especially with a molecular weightranging from 1200 to about 7000 are preferred.

Synthetic resins that can be stabilized with compositions comprising apolyhydric phenol and inorganic acid-carbonate coester according to thisinvention include alphaolefin polymers such as polyethylene,polypropylene, polybutene, poly-3-methylbutene, or copolymers thereofsuch as ethylenevinylacetate copolymer, ethylenepropylene copolymer,polystyrene, polyvinylacetate, acrylic ester resins, copolymers fromstyrene and another monomer (for example, maleic anhydride, butadiene,acrylonitrile and so on), acrylonitrile-butadiene-styrene copolymer,acrylic acid ester-butadiene-styrene copolymer, methacrylic acicester-butadiene-styrene copolymer, methacrylate ester resin such aspolymethylmethacrylate, polyvinylalcohol, ethylene and butyleneterephthalate polyesters, polyamide, polycarbonate, polyacetal,polyurethane, cellulosic resin, or phenolic resin, urea resin, melamineresin, epoxy resin, unsaturated polyester, silicone resin,halogen-containing resins such as polyvinyl chloride, polyvinylidenechloride, polyvinylidene fluoride and copolymers thereof, and furtherrubbers such as isoprene rubber, chloroprene rubber, and blends of theabove resins.

Stabilizer compositions comprising a polyhydric phenol inorganicacid-carbonate coester according to this invention can be formulated andmarketed in liquid, solid, and paste forms. An inert solvent can be usedto facilitate handling. The polyhydric phenol coester and known polymerstabilizers can also be solubilized in one another by heating, such asat 70°-160° C. for up to 4 hours, and then allowing the resulting meltto cool and harden sufficiently to be flaked and ground.

Known polymer stabilizers can be used in synthetic resin compositionstogether with the coester stabilizers of this invention and can beadmixed with the latter. Such stabilizers include thiodipropionic acidesters, polyvalent metal salts of carboxylic acids, organic phosphites,1,2-epoxides, polyhydric alcohols, polyhydric alcohol3-alkylthiopropionic acid esters, ultraviolet absorbers and heavy metaldeactivators. Representative thiodipropionic acid esters includedi-n-dodecyl thiodipropionate, dihexadecyl thiodipropionate, distearylthiodipropionate, n-octyl eicosanyl thiodipropionate and n-octadecylcyclohexane-1,4-dimethanol thiodipropionate polyester. A comprehensivedisclosure of useful thiodipropionate esters by M. Minagawa et al inU.S. Pat. No. 3,869,423, column 17 line 55 to column 19 line 54 is hereincorporated by reference. When thiodipropionate esters are used theconcentration based on 100 parts of polymer can range from 0.05 to about0.75 parts by weight.

Representative polyvalent metal salts include zinc, calcium, magnesium,barium, strontium and nickel salts of monocarboxylic acids having 6 to24 carbon atoms, for example zinc benzoate, calcium palmitate, andnickel 2-ethylbutyrate. A comprehensive disclosure of useful metal saltsby M. Minagawa et al in U.S. Pat. No. 3,869,423, column 19 line 56column 20 line 35 is here incorporated by reference. When metal saltsare used the concentration based on 100 parts by weight of polymer canrange from 0.1 to about 3 parts by weight.

Representative organic phosphites include triisodecylphosphite, tris(nonylphenyl phosphite), and 4,4'-isopropylidene diphenol alkyl (C₁₂-C₁₅) phosphite. A comprehensive disclosure of useful organic phosphitesby M. Minagawa in U.S. Pat. No. 3,849,370 column 13 line 63 to column 16line 48 is here incorporated by reference. Typical use concentrations oforganic phosphites are in the range from 0.02 part to about 2 parts byweight per 100 parts of polymer being stabilized.

Representative 1,2-epoxides that can be used in stabilizer compositionsaccording to this invention include epoxysoybean oil, epoxylinseed oil,and 2-ethylhexyl epoxystearate. A comprehensive disclosure of1,2-epoxides by M. Minagawa et al in U.S. Pat. No. 3,869,423 column 26line 13 to line 39 is here incorporated by reference. Typical useconcentrations of 1,2-epoxides range from 0.3 to about 6 parts by weightper 100 parts of synthetic resin composition.

Aliphatic polyhydroxy compounds can be included with stabilizercompositions of this invention in amounts corresponding to 0.1 to about1 part per 100 parts of polymer being stabilized. Typical aliphaticpolyhydroxy compounds are glycerol, polyglycerol, monodi-, andtri-pentaerythritol, mannitol, sorbitol, and partial esters of thesewith saturated and unsaturated fatty acids having 6 to 22 carbon atoms.

3-Alkylthio propionates of polyhydric alcohols can be included instabilizer compositions of this invention in amounts corresponding to0.02 to about 1 part per 100 parts of synthetic resin being stabilized.The propionate esters have 4 to about 34 carbon atoms in thealkylthiopropionate group, 2 to about 15 carbon atoms in the polyhydricalcohol group and 2 to about 8 ester groups in the molecule.Representative propionate esters are 2,2-dimethylpropanediol bis(3-n-dodecylthio-2-methylpropionate), pentaerythritoltetrakis(3-n-octylthiopropionate) and tris(3-n-octadecylthiopropionyloxyethyl)isocyanurate. For a further listingof useful 3-alkylthiopropionates the disclosure of A. Onishi U.S. Pat.No. 3,629,194 can be consulted.

Ultraviolet absorbers can be included in stabilizer compositions of thisinvention in amounts corresponding to 0.05 to about 1 part per 100 partsof synthetic resin being protected. Typical ultraviolet absorbers are2-hydroxybenzophenones such as 2-hydroxy-4-n-octyloxybenzophenone and2,4-dihydroxybenzophenone, and 2-(2'hydroxyphenyl)benzotriazoles such as2-(2'-hydroxy-5'-methylphenylbenzotriazole and2-(2'-hydroxy-5'-t-butylphenyl) 5,6-dichlorobenzotriazole. For a furtherlisting of many useful ultraviolet absorbers the disclosure of U.S. Pat.No. 3,395,112 of July 30, 1968, particularly column 14 line 40 to column19 line 33, can be consulted. Stabilizer compositions according to thisinvention that protect synthetic resin compositions used in contact withmaterials containing heavy metals and their compounds, as in insulatingmaterials for copper based electrical conductors or in compositionspigmented with heavy metal containing pigments such as rouge, talc, andiron-bearing asbestos, can contain heavy metal deactivators thatcounteract the prodegradant effect of the heavy metal on synthetic resincompositions that would be satisfactorily stabilized in the absence ofheavy metal. Heavy metal deactivators that can be used in stabilizercompositions according to this invention include melamine,dicyandiamide, oxanilide, N,N'-disalicyloylhydrazine,3-salicyloylamido-1,2,4-triazole, as well as the heavy metaldeactivators disclosed by M. Minagawa in U.S. Pat. Nos. 3,549,572(column 5 line 19 to column 10 line 23), 3,629,181 (column 5 line 15 tocolumn 9 line 54), 3,673,152 (column 4 line 47 to column 8 line 62), and3,849,370 (column 5 line 5 to column 13 line 45). These disclosures arehere incorporated by reference. Illustrative of stabilizer compositionscomprising coesters of polyhydric phenols with carbonic acid and aninorganic acid according to this invention together with known polymerstabilizers are the following:

    ______________________________________                                        STA-                                                                          BIL-                                                                          IZER                                                                          COM-                           PARTS                                          POST-                                                                         TION     INGREDIENTS           WEIGHT                                         ______________________________________                                        I     2:1 (molar ratio) carbonate/borate                                            of 4,4'-butylidenebis(3(methyl-6-t-                                           butylphenol), approx. mol. wt. 1400                                                                    10                                                   Zinc Stearate            20                                                   Magnesium benzoate       15                                                   Mannitol                 25                                             II    2:3 carbonate/phosphate of bis(3-methyl-                                      4-hydroxy-5-t-butylbenzyl)sulfide,                                            approx. mol. wt. 1900    12                                                   Barium nonylphenolate    30                                                   Zinc 2-ethylhexoate      18                                                   Diphenyl isodecyl phosphite                                                                            40                                             III   2:5 carbonate/p-cresylphosphate of 2,3,5-                                     trimethyl-hydroquinone, approx. mol wt.                                       2900                     25                                                   2-ethylhexyl epoxystearate                                                                             45                                                   tris(nonylphenyl) phosphite                                                                            30                                             IV    4:3 carbonate/o-t-butylphenylphosphate                                        of 4,4'-isopropyl-idenediphenol, approx.                                                               10                                                   mol. wt. 2400                                                                 Strontium laurate        80                                                   Zinc laurate             40                                                   Dipentaerythritol        15                                             V     1:1 carbonate/ phosphite of 2,2'-                                             methylenebis(4,6-di-t-butylphenol),                                           approx. mol. wt. 900     25                                                   Distearyl thiodipropionate                                                                             45                                                   Trihexadecyl phosphite   10                                             VI    2:1 carbonate/2-ethylhexylphosphite of t-                                     butylhydroquinone, approx. mol. wt. 4600                                                               60                                                   Dicyandiamide            40                                             VII   3:1 carbonate/borate of 4,4'-                                                 thiobis(2-t-butyl-5-methylphenol),                                            approx. mol. wt. 3300    15                                                   Pentaerythritol bis(n-octadecyl                                               phosphite)               6                                              VIII  1:1 carbonate/acid phosphite of 1,1,3-                                        tris(2'-methyl-4'-hydroxy-5'-t-butylphenyl)butane-                            approx. mol. wt. 2200    15                                                   Trimethylolpropane tris(3-iso-                                                tridecylthiopropionate)  55                                                   2(2'-hydroxy-5'-methylphenyl)                                                 benzotriazole            15                                             IX    3:2-carbonate/phosphate of 4,4'-                                              cyclohexylidenebis(2-t-butyl-                                                 phenol), approx. mol. wt. 5600                                                                         32                                                   di-isotridecylthiodipropionate                                                                         20                                                   Calcium myristate        28                                                   N,N'-disalicyloylhydrazine                                                                             20                                             ______________________________________                                    

The preparation of the stabilized resin composition is easilyaccomplished by conventional procedures. A heated two roll mill, forexample, is a convenient compounding tool for blending stabilizercompositions of the invention with polyolefins, vinyl chloride polymers,ABS polymers, ethylene-vinyl acetate copolymers and others.

The Examples that follow illustrate the invention without limiting itsscope. Examples 1 through 24 describe the preparation of differentpolyhydric phenol inorganic acid and carbonic ester coesters of thisinvention by several of the techniques disclosed above. Examples 25through 87 illustrate the use of coester stabilizers of this inventionand stabilizer compositions comprising coesters of this invention in thestabilization of olefin polymers, a vinyl chloride polymer an ABSpolymer, and a polyamide.

EXAMPLES 1-7

Triphenylphosphite (TPP) 31.0 g (0.1 mole),4,4'-n-butylidenebis(3-methyl-6-t-butylphenol) 190.0 g (0.5 mole), 64.2g (0.3 mole) diphenyl carbonate (DPC) and 0.3 g potassium carbonate wereheated at 160° C. under the nitrogen atmosphere. Then vacuum was appliedfor 2 hours while distilling out phenol under reduced pressure (3 mmHg). The quantity of phenol distillate was 65.2 g or 0.69 molerepresenting 76% of the maximum calculated (3 mm Hg) quantity.

A pale yellow solid of M.P. 110°-120° C., molecular weight 1880 wasobtained (stabilizer No. 1). The molecular weight was measured by avapor pressure method.

The following polyhydric phenol coester compounds in Table 1 wereobtained by the same procedure as Example 1 by varying the polyhydricphenol and the molar proportions of the reactants.

                                      TABLE 1                                     __________________________________________________________________________    STABILIZER                                                                            POLYHYDRIC PHENOL                                                                             MOLAR RATIO                                                                            MELTING                                                                              APPROXIMATE                           NO.     (PHP)           TPP:DPC:PHP                                                                            POINT °C.                                                                     MOLECULAR WEIGHT                      __________________________________________________________________________    2       Bisphenol A     2:2:5    75-80  1,290                                 3       Hydroquinone    2:2:5    120-152                                                                                850                                 4       4,4'Thiobis(3-methyl-6-t-                                                     butyl)phenol    1:4:6    125-136                                                                              2,100                                 5       4,4'-cyclohexylidene bis(2-                                                   cyclohexylphenol)                                                                             1:2:4     80-100                                                                              1,700                                 6       4,4'-isopropylidene bis(2-t-                                                  butylphenol)    3:1:5    67-75  1,900                                 7       1,1,3-tris(2'-methyl-5'-t-                                                    butyl-4'-hydroxyphenyl)butane                                                                 2:1:4    81-93  2,200                                 __________________________________________________________________________

EXAMPLES 8-15

Diphenyl 2-ethylhexylphosphite (DEP) 69.2 g (0.2 mole),diphenylcarbonate (DPC) 64.2 g (0.3 mole) and 136.8 g (0.6 mole)bisphenol A and potassium carbonate 0.26 g were reacted at 140° C. for 3hours under nitrogen and then 24 hours more under reduced pressure (3 mmHg) while distilling out 85.1 g phenol (0.91 mole) or 75% of the maximalcalculated quantity.

A colorless glassy solid of m.p. 54°-58° C., m.w. 1600 was obtained.(stabilizer No. 8).

In the same way as EXAMPLE 8, the compounds obtained by varying thepolyhydric phenol and the molar proportions of reactants are shown inTable 2.

                                      TABLE 2                                     __________________________________________________________________________                                  MOLAR RATIO                                                                            MELTING POINT                          EXAMPLE NO.                                                                            POLYVALENT PHENOL (PVP)                                                                            DEP:DPC:PVP                                                                            (°C.)                                                                            M. W.                        __________________________________________________________________________     9       4,4'-n-butylidene bis (2-t-butyl-5-                                           methyl phenol)       1:1:3    45-62  1535                            10       4,4' -cyclohexylidene diphenol:2,2-                                           bis(3-t-butyl-4-hydroxyphenyl)                                                4-(3,5-di-t-butyl-4-hydroxy phenyl)                                           butane (2:2 mixture) 2:1:4    --     1272                            11       2,2-bis(3-t-butyl-4-hydroxyphenyl)                                            butane               2:1:2    --     1486                            12       4,4'-thiobis(2-t-butyl-6-methyl phenol)                                                            4:1:6    --     3425                            13       4,4'-methylene bis(2-t-butyl-6-methyl phenol)                                                      3:2:4    --     1697                            14       Bis phenol A:4,4'-n-butylidene bis(2-t-butyl-                                 5-methylphenol) (2:2 mixture)                                                                      1:2:4    50-63  1287                            15       Bis phenol A         2:5:8    80- 2043                               __________________________________________________________________________

EXAMPLES 16-19

65.2 g (0.2 mole) of triphenylphosphate (TPPa),

42.8 g (0.2 mole) of diphenylcarbonate (DPC),

191.0 g (0.5 mole) of 4,4'-n-butylidenebis(2-t-butyl-5-methyl phenol)and

0.4 g of potassium carbonate were reacted for 3 hours at 165° C. under anitrogen stream, and then 56.4 g (0.6 mole) of produced phenol wasdistilled out during 3 hours in vacuum (3 mmHg).

A pale yellow glassy solid was obtained (EXAMPLE No. 16) having a m.p.85°-97° C. and M.W. 1723.

The compounds of EXAMPLES No. 17-19 were prepared according to the sameprocedure as EXAMPLE 16 and described in TABLE 3.

                                      TABLE 3                                     __________________________________________________________________________                              MOLAR RATIO                                                                            M.P.                                       EXAMPLE No.                                                                            POLYVALENT PHENOL (PVP)                                                                        TPPa: DPC:PVP                                                                          (°C.)                                                                       M.W.                                  __________________________________________________________________________    17       4,4'-isopropylidene bis                                                       (2-t-butyl phenol)                                                                             1:3:5     97-115                                                                            989                                   18       4,4'-thiobis(3-methyl-6-                                                      t-butylphenol)   2:1:2    81-93                                                                              814                                   19       1,1,3-tris(2-methyl-4-                                                        hydroxy-5-t-butylphenyl)                                                      butane           1:2:3    112-117                                                                            1457                                  __________________________________________________________________________

EXAMPLES 20-23

58.0 g (0.2 mole) of triphenyl borate (TPB), 42.8 g (0.2 mole) ofdiphenyl carbonate (DPC), 191.0 g (0.5 mole) of 4,4'-butylidenebis(2-t-butyl-5-methyl phenol) and 0.2 g of potassium carbonate werereacted for 3 hours at 150° C. under a nitrogen stream and then 71.4 g(0.76 mole) of produced phenol was distilled out during 3 hours invacuum (3 mm Hg).

The compounds of EXAMPLES NO. 21-23 were prepared according to the sameprocedure as EXAMPLE 20 and described in TABLE 4.

                                      TABLE 4                                     __________________________________________________________________________    EXAMPLE                    MOLAR RATIO                                                                            MELTING POINT                             NO.    POLYVALENT PHENOL (PVP)                                                                           TPB:DPC:PVP                                                                            (°C.)                                                                            M.W.                            __________________________________________________________________________    21     Bisphenol A         2:1:5    62-67     1147                            22     2,2-bis(3-t-butyl-4-                                                          hydroxy phenyl)-4-3,                                                          5-di-t-butyl-4-(hydroxy                                                       phenyl)butane       1:2:4    84-90     2154                            23     4,4'-cyclohexylidene                                                          bis(2-cyclohexylphenol)                                                                           2:2:3    56-69     1396                            __________________________________________________________________________

EXAMPLE--24

46.8 g (0.2 mole) of diphenyl hydrogen phosphite, 42.8 g (0.2 mole) ofdiphenyl carbonate, 114.0 g (0.5 mole) of bisphenol A and 0.2 g ofpotassium carbonate were reacted for 3 hours at 160° C. under nitrogenstream, and then 70.4 g (0.75 mole) of produced phenol was distilled outduring 2 hours in vacuum (3 mmHg).

A pale yellow solid was obtained having m.p. 80°-90° C.

The compounds mentioned avove were tested for polypropylene,polyethylene, polybutene-1, ABS, PVC, polyamide and ethylene-vinylacetate copolymer as antioxidant, as described in the followingexamples.

EXAMPLES 25-32

Substantially unstabilized polypropylene resin (Profax 6501, containinga trace of BHT antioxidant to protect the polymer during shipment andstorage only) 100 parts by weight, dilaurylthiodipropionate 0.2 parts byweight, and polyhydric phenol inorganic acid carbonate coester 0.2 partby weight were mixed for ten minutes by mixing and grinding at roomtemperature and milled and molded to make a sheet of 1.0 mm in thicknessat 180° C. and 200 kg/cm² for 5 minutes. From this sheet were cut tensample pieces of 10×20 mm of each formulation, and exposed on aluminumfoil in a Geer air-circulating oven at 160° C. for heat stabilityexamination. Ten additional sample pieces of the same size cut from eachsheet were kept for 7 days in water at 90° C. and then oven tested at160° C. to test the resistance of the stabilizer against being leachedor otherwise rendered ineffective. The time to the beginning ofdegradation was taken as the time when more then five sample pieces inten of each formulation were discolored and brittle.

The stabilizer ingredients used and the results obtained are shown inTABLE 5.

                  TABLE 5                                                         ______________________________________                                                                            Steeped                                                                       in hot                                    No.                     Deterioration                                                                             water                                     Control                                                                              Stabilizer       Beginning Time                                                                            (7 days)                                  ______________________________________                                        A      4,4'-n-butylidenebis(3-                                                       methyl-6-t-butylphenol)                                                                        490 hours   250                                                                           hours                                     B      NONE             110          90                                       EXAMPLE                                                                              Polyhydric phenol coester                                              25     No. 1            1,300       1,180                                     26     No. 4            1,240       1,140                                     27     No. 5            1,270       1,200                                     28     No. 11           1,290       1,170                                     29     No. 14           1,150       1,080                                     30     No. 17           1,070       1,040                                     31     No. 20           1,270       1,150                                     32     No. 24           1,100       1,060                                     ______________________________________                                    

Each of the polypropylene samples of Examples 30 through 37 stabilizedaccording to this invention with a coester of carbonic acid and aninorganic acid with a polyhydric phenol had when freshly prepared atleast double the heat stability of a control composition containing aconventional phenolic stabilizer along with the same dilaurylthiodipropionate synergist, used in EXAMPLES 25-32. After the 7 dayimmersion test in hot water the difference was even more dramatic. Thesamples of Examples 25 through 32 stabilized according to this inventionhad substantially retained their heat stability while the controlcomposition had retained only about one half the original heatstability.

EXAMPLES 33-40

Stabilized polyethylene resin (Hi-Zex 5100E, Mitsui PetrochemicalIndustries, Ltd. Japan) 100 parts by weight and a polyhydric phenolinorganic acid-carbonate coester 0.15 part by weight were milled on atwo roll mill for 5 minutes at 150° C. and then molded into a sheet of1.2 mm thickness by compression molding at 150° C. and 180 kg/cm² for 5minutes. The sheet was cut into sample pieces of 10×20 mm and tested forheat stability in the Geer oven at 148.5° C. in air on aluminum foil.The time to the beginning of degradation was taken as the time when morethan five sample pieces in ten of each formulation were discolored andwaxy. The stabilizer ingredients used and the results obtained are shownin Table 6.

                  TABLE 6                                                         ______________________________________                                        No.                         Deterioration                                     Control STABILIZER          Beginning Time                                    ______________________________________                                        C       1,1,3-tris(2'-methyl-4'-hydroxy                                               5' butylphenyl)butane                                                                             305 hours                                         D       Stearyl 3(3',5'-di-t-butyl-4'-                                                hydroxyphenyl)propionate                                                                          346                                               E       None                193                                               Example Polyhydric phenol coester                                             33      No. 6               427                                               34      No. 7               442                                               35      No. 9               455                                               36      No. 13              446                                               37      No. 6               412                                               38      No. 18              403                                               39      No. 22              450                                               40      No. 23              448                                               ______________________________________                                    

Each of the polyethylene samples of Examples 38 through 45 stabilizedaccording to this invention with a coester of carbonic acid and aninorganic acid with a polyhydric phenol had a 16 to 48% greater heatstability than a control sample stabilized instead with a known phenolicantioxidant.

EXAMPLES 41-47

ABS resin (Blendex 111) 100 parts by weight, Zinc stearate 0.5 part byweight, titanium dioxide 5.0 parts by weight, and a polyhydric phenolinorganic acid-carbonate coester 0.5 part by weight were mixed bygrinding at room temperature for 10 minutes.

The compound was prepared by extruding the ground mixture using a 30 mmextruder at 30 rpm and 240° C. A sheet of 0.5 mm thickness was preparedby compression molding each extruded compound at 200 kg/cm² and 180° C.for 5 minutes. Each molded sheet was cut to the size of 40×150 mm, andsuspended in an individual glass cyclinder.

Each cylinder was set in an air circulating oven at 140° C., flushedwith pure oxygen, the pressure adjusted to one atmosphere, and thecyclinder fitted with a closed end manometer. The time to beginning ofoxidation-degradation was read by recording the time when the pressurein the cylinder diminished rapidly. The ingredients of the stabilizercombination used in each example and the results observed are shown inTable 7.

                  TABLE 7                                                         ______________________________________                                        No.                      DETERIORATION                                        Control STABILIZER       BEGINNING TIME                                       ______________________________________                                        F       None             160 minutes                                          G       4,4'-thiobis(3-methyl-6-t-                                                    butylphenol)     240                                                  Example Polyhydric Phenol Coester                                             41      No. 2            580                                                  42      No. 5            530                                                  43      No. 8            590                                                  44      No. 10           570                                                  45      No. 15           580                                                  46      No. 16           510                                                  47      No. 17           540                                                  ______________________________________                                    

Each of the ABS polymer samples of Examples 41 through 47 stabilizedaccording to this invention with a coester of carbonic acid and aninorganic acid with a polyhydric phenol had at least double the heatstability of a control sample stabilized with the same zinc stearate asin Examples 41 through 47 along with a conventional polyhydric phenolstabilizer.

EXAMPLES 48-55

A clear sheet was prepared by kneading polyvinylchloride resin (Geon103EP) 100 parts, dioctylphthalate 42 parts, epoxidized soybean oil 3parts, zinc stearate 0.3 part, barium stearate 0.5 part, stearic acid0.3 part, and a polyhydric phenol inorganic acid-carbonate coester 0.3part on a two roll mill at 175° C. for 5 minutes and then compressionmolding at 175° C. Then, a heat stability test was carried out in a Geeroven at 190° C. in an air atmosphere. The time to degradation time wasdetermined by the discoloration observed. The polyhydric phenol coesterused and the results obtained are shown in Table 8.

                  TABLE 8                                                         ______________________________________                                                                 BEGINNING TIME                                       No.                      OF DETERIORATION                                     Control STABILIZER       Yellowed  Blackened                                  ______________________________________                                        H       None             30 min.   40 min.                                    I       BHT              35        45                                         EXAMPLE Polyhydric phenol coester                                             48      No. 3            65        80                                         49      No. 6            60        75                                         50      No. 9            60        75                                         51      No. 10           65        80                                         52      No. 15           70        85                                         53      No. 17           50        65                                         54      No. 23           60        80                                         55      No. 24           65        85                                         ______________________________________                                    

Each of the polyvinyl chloride samples of Examples 28 through 55stabilized according to this invention with a coester of carbonic acidand an inorganic acid with a polyhydric phenol, along with epoxidizedsoybean oil, zinc stearate, and barium stearate, had at least 43%greater heat stability than a control sample containing a conventionalhindered phenol along with the same epoxidized soybean oil, zincstearate, and barium stearate.

EXAMPLE 56-63

100 parts of nylon 66 delustered by adding 0.05% of titanium dioxide wasdissolved in 90 parts of 90% formic acid, and 1.0 part of a polyhydricphenol inorganic acid-carbonate coester was added and mixed completely.The solution was flowed uniformly on a glass plate, and dried in aheated air oven at 105° C. for 10 minutes to prepare a film. The colorof the film, after being heated in an air oven at 225° C. for 30minutes, was measured and shown in Table 9 along with the compoundspresent in each formulation.

                  TABLE 9                                                         ______________________________________                                        No.      Stabilizer         Color of Sheet                                    ______________________________________                                        Control                                                                       J        None               dark brown                                        K        4,4'-cyclohexylidene                                                                             brown                                                      Bisphenol                                                            EXAMPLE  Polyhydric phenol coester                                            56       No. 2              light yellow                                      57       No. 4              "                                                 58       No. 8              "                                                 59       No. 11             "                                                 60       No. 12             "                                                 61       No. 19             Yellow                                            62       No. 20             light yellow                                      63       No. 23             light yellow                                      ______________________________________                                    

Each of the nylon samples of Example 56 through 63 stabilized accordingto this invention with a coester of carbonic acid and an inorganic acidwith a polyhydric phenol gave a much lighter colored film than controlsamples containing instead of the coester according to this invention aconventional polyhydric phenol stabilizer or no stabilizer.

EXAMPLE 64 TO 77

In order to examine the effect of the stabilizer according to thisinvention on polybutene resin, a sheet of 1 mm in thickness was preparedby kneading the following formulation on a two roll mill and thencompression molding at 160° C. and 200 kg/cm² for 5 minutes. The sheetobtained was cut to the size of 40×150 mm, and tested for heat stabilityin glass cylinders containing pure oxygen at 1 atmosphere pressure as inExample 41 to 47, except that the test temperature was 160° C.

    ______________________________________                                        (Formulation)                                                                 Un-stabilized poly-1-butene resin                                                                  100 parts by weight                                      Calcium stearate      1.0                                                     Distearylthiodipropionate                                                                           0.2                                                     Polyhydric phenol inorganic acid                                                                    0.2                                                     carbonate coester                                                             ______________________________________                                    

The results are shown in Table 10. The time to beginning of oxidationdegradation was read by recording the time when the pressure in thecylinder diminished rapidly.

                  TABLE 10                                                        ______________________________________                                                                   Deterioration                                      No.        Stabilizer      Beginning Time                                     ______________________________________                                        Control                                                                       L          BHT            97 hrs                                              M          4,4-butylidenebis                                                                            224                                                            (3-methyl-6-t-butyl-                                                          phenol)                                                                       Polyhydric phenol                                                  Example    coester                                                            64         No.1           570                                                 65         No.3           523                                                 66         No.7           546                                                 67         No.12          561                                                 68         No.14          545                                                 69         No.19          506                                                 70         No.20          568                                                 71         No.21          517                                                 ______________________________________                                    

Each of the polybutene samples of EXAMPLES 64 through 71 stabilizedaccording to this invention with a coester of carbonic acid and aninorganic acid with a polyhydric phenol had at least double the heatstability of a control sample stabilizer with the samedistearylthiodipropionate and calcium stearate as in Example 64 through71 along with a conventional polyhydric phenol stabilizer.

EXAMPLE 72-79

In order to examine the effects of the coesters according to thisinvention in ethylene-vinylacetate copolymer, samples were preparedaccording to the following formulation and tested for heat stability ina Geer oven at 175° C. and initial color was measured for yellownessusing the Hunter color difference meter, greater numbers indicating moresevere discoloration. The results are shown in Table 11. The heatstability is expressed in minutes of heating in the oven until a red orbrown discoloration was observed.

    ______________________________________                                        (Formulation)                                                                 Ethylene-Vinylacetate copolymer resin                                                                    100 parts                                          Montan wax ester lubricant  0.3                                               Polyhydric phenol Inorganic acid-carbonate ester                                                          0.1                                               ______________________________________                                    

                  TABLE 11                                                        ______________________________________                                                                            Initial                                   No.    Sample Compound  Heat Stability                                                                            Color                                     ______________________________________                                        Control                                                                              Stabilizer                                                             N      None             75 min      35                                        O      4,4-butylidenebis                                                                              90          28                                               (3-methyl-6-t-butyl-                                                          phenol)                                                                Example                                                                              polyhydric phenol coester                                              72     No. 1            150         9                                         73     No. 5            150         10                                        74     No. 7            135         12                                        75     No. 9            150         10                                        76     No. 13           135         11                                        77     No. 18           120         10                                        78     No. 22           135         11                                        79     No. 24           120         9                                         ______________________________________                                    

Each of the ethylene-vinylacetate copolymer samples of Example 78through 85 stabilized according to this invention with a coester ofcarbonic acid and an inorganic acid with a polyhydric phenol had muchlighter initial color and at least 33% greater heat stability than acontrol sample stabilized with a conventional polyhydric phenol.

EXAMPLES 80-87

The stabilizer combinations according to this invention have anexcellent stabilizing effect on crosslinked polyethylene. Unstabilizedlow density polyethylene(meltindex 2.0) 100 parts by weight,dilaurylthiodipropionate 0.2 part by weight, and a polyhydric phenolinorganic acid and carbonate coester 0.2 part by weight were mixed bymilling on a two roll mill at 110° C. for 10 minutes and then dicumylperoxide (Percumyl D, Nippon Oil and Fats Co., Ltd) 2.0 parts by weightwas added and further kneaded at the same temperature for two minutes.This sheet prepared on the mill was compression molded at 110° C. and100 kg/cm² for 5 minutes, then rapidly heated up to 180° C. whilemaintaining the pressure at 100 kg/cm² for 15 minutes. The sheetobtained was cut to the size of 40×150 mm, hung in a Geer oven andtested for heat stability in air at 160° C. The degradation time wasjudged by looking for the time when more than 50% of pieces werediscolored or deformed. The stabilizer ingredients used and the resultsobtained are shown in Table 12.

                  TABLE 12                                                        ______________________________________                                                                   Beginning Time                                     No.      Sample Compound   of Aging                                           ______________________________________                                        Control Stabilizer                                                            P       BHT                34 hrs                                             Q       4,4-thiobis(3-methyl-6-t-                                                                        110                                                        butylphenol)                                                          Example Polyhydric phenol coester                                             80      No. 1              176                                                81      No. 4              184                                                82      No. 7              166                                                83      No. 9              172                                                84      No. 14             163                                                85      No. 18             179                                                86      No. 20             165                                                87      No. 23             160                                                ______________________________________                                    

Each of the cross-linked polyethylene samples of Example 86 through 93stabilized according to this invention with a coester of carbonic acidand an inorganic acid with a polyhydric phenol had at least 46% greaterheat stability than a control sample stabilized with a conventionalpolyhydric phenol.

We claim:
 1. As a new composition of matter, a coester terminating in afree hydroxyl group and having a molecular weight between 700 and about10,000, of at least one polyhydric phenol having 3 phenolic hydroxylgroups and 3 benzenoid rings substituted with zero to three alkyl,cycloalkyl, or aralkyl groups having 1 to 10 carbon atoms, with carbonicacid and an inorganic acid selected from the group consisting ofphosphorous acid and phosphoric acid, in which the molar proportions ofcarbonic acid to inorganic acid range from 19:1 to 1:19.
 2. A coesteraccording to claim 1 having a molecular weight between 1200 and about7000.
 3. A coester according to claim 1 in which the inorganic acid isphosphorous acid.
 4. A coester according to claim 1 in which theinorganic acid is phosphoric acid.
 5. A coester according to claim 4which is a carbonate-acid phosphite coester.
 6. A coester according toclaim 4 which is a carbonate-phenol phosphate coester.
 7. A coesteraccording to claim 1 in which the polyhydric phenol is 1, 1,3-tris(2'-methyl-4'-hydroxy-5'-t-butylphenyl)butane.
 8. A stabilizercomposition capable of increasing the resistance to deterioration onheating of a synthetic resin, comprising a coester terminating in a freehydroxyl group and having a molecular weight between 700 and about10,000, of at least one polyhydric phenol having 2 to 3 phenolichydroxyl groups and 1 to 3 benzenoid rings, substituted with zero tothree alkyl, cycloalkyl or aralkyl groups having 1 to 10 carbon atoms,with carbonic acid and an inorganic acid selected from the groupconsisting of phosphorous acid and phosphoric acid, in which the molarproportions of carbonic acid to inorganic acid range from 19:1 to 1:19,and at least one synthetic resin stabilizer selected from the groupconsisting of thiodipropionate esters, organic phosphites, polyhydricalcohols, polyhydric alcohol 3-alkylthio propionates, ultravioletabsorbers, heavy metal deactivators, and barium, calcium, magnesium,nickel, strontium, tin, and zinc salts of monocarboxylic acids having 6to 24 carbon atoms.
 9. A stabilizer composition according to claim 8 inwhich the synthetic resin stabilizer is a thiodipropionate ester.
 10. Astabilizer composition according to claim 8, in which the inorganic acidof the coester is phosphorous acid.
 11. A stabilizer compositionaccording to claim 8, in which the polyhydric phenol of the coester isan alkylidenebisphenol.
 12. A stabilizer composition according to claim11 in which the alkylidenebisphenol is4,4'-n-butylidenebis(2-t-butyl-5-methylphenol).
 13. A stabilizercomposition according to claim 8, in which the synthetic resinstabilizer is a barium, calcium, magnesium, nickel, strontium, tin, orzinc salt of a monocarboxylic acid having 6 to 24 carbon atoms.
 14. Astabilizer composition according to claim 13, in which the syntheticresin stabilizer is calcium stearate.
 15. A stabilized synthetic resincomposition comprising a synthetic resin selected from the groupconsisting of olefin polymers, vinyl chloride polymers, acrylonitrilecopolymers, and polyamides comprising a synthetic resin and 0.05 to 5percent by weight of the resin of a coester terminating in a freehydroxyl group and having a molecular weight between 700 and about10,000, of at least one polyhydric phenol having 2 to 3 phenolichydroxyl groups and 1 to 3 benzenoid rings, substituted with zero tothree alkyl, cycloalkyl, or aralkyl groups having 1 to 10 carbon atoms,with carbonic acid and an inorganic acid selected from the groupconsisting of phosphorous acid and phosphoric acid, in which the molarproportions of carbonic acid to inorganic acid range from 19:1 to 1:19.16. A stabilized synthetic resin composition according to claim 15 inwhich the synthetic resin is an olefin polymer.
 17. A stabilizedsynthetic resin composition according to claim 15 in which the syntheticresin is a vinyl chloride polymer.
 18. A stabilized synthetic resincomposition according to claim 15 in which the inorganic acid of thecoester is phosphorous acid.
 19. A stabilized synthetic resincomposition according to claim 18 in which the coester is a phenyl esterof phosphorus acid.
 20. A stabilized synthetic resin compositionaccording to claim 18 in which the coester is a 2-ethylhexyl ester ofphosphorous acid.